Some 20 million tonnes of oils and fats are used for various frying activities around the world (Gertz, 2000, 2001). In the United States, it was estimated that the fast food restaurants used several million tonnes of frying oils and fats annually (Warner and Neff, 2001). During frying operations, usually carried out between 160°C-190°C, complex reactions including dehydration, oxidation, hydrolysis, polymerization, cyclization, etc. take place which affects the economic use of the oils and fats and the shelf-life stability of the fried foods. A restaurant operator or industrial fryer is concerned about the cost and stability of the oil/fat during frying and its effect on the fried food quality. The stability of the oil/fat and its effect on the quality of fried foods depends among other things on the presence of unsaturated fatty acids, natural and/or added antioxidants, anti-foaming agent, fryer design, frying conditions, and the nature of the foods, etc.